you might already know that I am using NextAction! on my BlackBerry for GTD. The maker of NextAction! just started an open and free beta test for a new app called TaskMailer. I am using it successfully on my BB Curve (8320) which makes it f*** easy to email a task to my desktop task program (Apple Mail & iCal).
Just in case someone is interested: http://www.s4bb.com/the-beta-program/#taskmailer